General Management of the Rock Garden
The general management of theconsists in removing , keeping the surface as open as possible by occasionally disturbing it with a hoe or a special rockery tool, cutting off dead flowers (unless seed is required) and occasionally top dressing the surface of the pockets.
Top dressings vary according to the type of rockery plant being grown. Tender Alpines, which are apt to “ damp off” in very rainy or cold weather, are best top dressed with small stone chips. This slight attention will preserve many a tender rock plant in the open through worst winter days.
Where the soil gets washed away from the crowns of the plants from time to time, a top dressing of the followingcan be used: one part sharp sand, one part decayed leaves, two parts fibrous loam, all rubbed through a I-in. Sieve.
A little lime rubble, crushed, and used as a top dressing round some of the lime-loving plants is also beneficial.
, as a rule, like to remain where they are without disturbance for a number of years. Small rockeries in town and suburban gardens are apt, however, to become sour by the constant washing of impurities from the atmosphere, and it does no harm to rock plants if the rockery is treated in the same way as the herbaceous border; that is to say, if it is renovated triennially.
The best time to do this is towards the end of summer, when most of the rock garden plants are at rest. The large rocks may be removed, and the plants temporarily heeled into some other part of the garden. The rockery can then be completely renovated, adding some fresh soil, and dressing the old soil with lime for use again in the remade rockery. Lime helps to purify it. The rock garden will then be rebuilt on the lines already laid down, and the plants set back in position as the building proceeds.
THE ROCK GARDEN IN WINTER
Special care must be taken over the rock garden plants during the winter. Cold is not the chief trouble; rain and fogs are far worse problems. That is why a top dressing of stones is useful round the crowns of the plants. It prevents the collection of moisture on this vital part. It is also wise, in many cases, tothe plants by using bell-glasses or Alpine protectors, which take the form of sheets of glass supported by wires so that they are held roof-like above the tender plants, and divert the rains.